U.S. patent number 7,748,228 [Application Number 11/653,040] was granted by the patent office on 2010-07-06 for refrigeration system capable of multi-faceted operation.
This patent grant is currently assigned to The Delfield Company, LLC. Invention is credited to William E. Smith, Darrel Jay Walker, Harry Edward Wing.
United States Patent |
7,748,228 |
Walker , et al. |
July 6, 2010 |
Refrigeration system capable of multi-faceted operation
Abstract
A storage system that has variable temperature includes one or
more drawers. The one or more drawers are independently operable of
one another. A heating and cooling system is in thermal
communication with the one or more drawers. The heating and cooling
system generates even air-flow around all sides of the one or more
drawers for heating and/or cooling thereof.
Inventors: |
Walker; Darrel Jay (Mt.
Pleasant, MI), Smith; William E. (Land O'Lakes, FL),
Wing; Harry Edward (Midland, MI) |
Assignee: |
The Delfield Company, LLC (Mt.
Pleasant, MI)
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Family
ID: |
38288156 |
Appl.
No.: |
11/653,040 |
Filed: |
January 12, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070180849 A1 |
Aug 9, 2007 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60758871 |
Jan 13, 2006 |
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Current U.S.
Class: |
62/258; 62/198;
62/382 |
Current CPC
Class: |
F25D
25/025 (20130101); F25D 31/005 (20130101); F25D
11/006 (20130101); F25D 29/00 (20130101); F25D
2400/16 (20130101); F25D 2400/361 (20130101); F25D
2700/121 (20130101); F25B 2400/06 (20130101) |
Current International
Class: |
F25D
23/12 (20060101) |
Field of
Search: |
;62/258,382,125-127,404-426,198-200,246-256,440-441 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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260493 |
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Sep 1996 |
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NZ |
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WO 2005/024314 |
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Mar 2005 |
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WO |
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WO 2005/024315 |
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Mar 2005 |
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WO |
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Other References
Examination Report dated Dec. 10, 2009 from corresponding New
Zealand Patent Application No. 566766. cited by other.
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Primary Examiner: Tapolcai; William E
Attorney, Agent or Firm: Ohlandt, Greeley, Ruggiero &
Perle, L.L.P.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application
Ser. No. 60/758,871, filed Jan. 13, 2006, the disclosure of which
is incorporated herein by reference.
Claims
What is claimed is:
1. A storage system that has variable temperature, the system
comprising: a plurality of drawers, wherein each drawer is capable
of operating in any mode selected from the group consisting of
refrigerator mode, freezer mode, thaw cabinet mode, and blast
chiller mode, at any time when the storage system is in use,
independently of one another; and a heating and cooling system in
thermal communication with said plurality of drawers, said heating
and cooling system generating even air-flow around all sides of
said plurality of drawers for heating and/or cooling thereof,
wherein each of said plurality of drawers is disposed within an
associated housing assembly when in a closed position, such that
each of said plurality of drawers is exposed to the interior
atmosphere of said associated housing assembly, wherein each said
associated housing assembly for each of said plurality of drawers
is separate and apart from other associated housing assemblies for
others of said plurality of drawers disposed within said storage
system, and wherein each of said associated housing assemblies
further comprises an evaporator compartment separate and apart from
evaporator compartments of all other associated housing assemblies
in said storage system.
2. The system of claim 1, wherein said heating and cooling system
has at least one evaporator located at a rear compartment of said
plurality of drawers.
3. The system of claim 2, wherein said at least one evaporator has
an air duct to distribute cooled air evenly over a top opening of
each of said plurality of drawers.
4. The system of claim 3, wherein said air duct has a thermal
mass.
5. The system of claim 4, wherein said thermal mass is a gel
pack.
6. The system of claim 1, wherein said heating and cooling system
has at least one condenser, at least one compressor, and at least
one evaporator.
7. The system of claim 1, further comprising at least one condenser
fan.
8. The system of claim 1, further comprising a display for user
input.
9. The system of claim 1, wherein said plurality of drawers are
free of lids.
10. The storage system of claim 1, wherein each of said associated
housing assemblies further comprises an air duct disposed therein,
wherein said air flow passes through said air duct and about all
said sides of said drawer disposed within said associated housing
assembly.
11. A method for heating and/or cooling a storage system comprising
a plurality of drawers and a plurality of housing assemblies, the
method comprising: generating even air-flow around all sides of
said plurality of drawers by a heating and cooling system for
heating and/or cooling thereof; and operating each of said
plurality of drawers in any mode selected from the group consisting
of refrigerator mode, freezer mode, thaw cabinet mode, and blast
chiller mode, at any time when the storage system is in use,
independently of one another, wherein each of said plurality of
drawers is disposed within an associated housing assembly when in a
closed position, such that said drawer is exposed to the interior
atmosphere of said associated housing assembly, wherein each of
said associated housing assemblies for each of said plurality of
drawers is separate and apart from other associated housing
assemblies for others of said plurality of drawers disposed within
said storage system, and wherein each of said associated housing
assemblies further comprises an evaporator compartment separate and
apart from evaporator compartments of all other associated housing
assemblies in said storage system.
12. The method of claim 11, wherein said heating and cooling system
has at least one evaporator located at a rear compartment of said
plurality of drawers.
13. The method of claim 12, wherein said at least one evaporator
has an air duct to distribute cooled air evenly over a top opening
of each of said plurality of drawers.
14. The method of claim 13, wherein said air duct has a thermal
mass.
15. The method of claim 14, wherein said thermal mass is a gel
pack.
16. The method of claim 11, further comprising detecting a
temperature in said plurality of drawers.
17. The method of claim 11, further comprising storing one or more
parameters of the heating and/or cooling a storage system in a
memory.
18. The method of claim 11, further comprising inputting one or
more predetermined parameters.
19. The method of claim 11, further comprising sounding an alarm to
indicate a predetermined condition.
20. The method of claim 11, wherein each of said associated housing
assemblies further comprises an air duct disposed therein, wherein
said air flow passes through said air duct and about all said sides
of said drawer disposed within said associated housing assembly.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to refrigeration and, more
particularly, a refrigeration system capable of multi-faceted
operation.
2. Description of the Related Art
In the food service industry, there is a need for storing of food
items in refrigerators and freezers. Food items can be blast
chilled in order to reduce a temperature of the food items down to
a safe storage temperature for later consumption. Food items stored
in refrigerators and freezers commonly need to be thawed prior to
preparation and consumption. Typically, separate appliances are
required for refrigeration, freezing, thawing, and blast chilling
food items undesirably requiring the food items to be transferred
to multiple appliances. Different food items can require different
storage temperatures; however, food items stored in the same
refrigerator, freezer, thaw box, or blast chiller must all be
stored at a single temperature. Refrigerators, freezers, thaw
boxes, and blast chillers are typically large and undesirably
occupy large areas in a kitchen or storage area.
U.S. Pat. Nos. 6,915,657 and 6,901,767 to Wood provide a
refrigerator/freezer appliance having rectangular-fronted drawers
arranged one above another and housed in a cabinet. The interior of
the cabinet is divided by insulated lids, one for each drawer. When
the drawer is closed, the open top of its associated bin is closed
by an appropriate one of the lids. The lids include evaporator
elements of known type disposed in the lower face of each lid. A
refrigerator engine compartment includes an impeller exhausting
through apertures provided in the front face of the refrigerator
engine compartment. Ambient air enters the appliance where it
immediately comes into contact with the outer surfaces of the bins
and warms them to ambient temperature before being drawn towards a
void and then upwards through the void by circulation of the air to
minimize condensation. Wood undesirably requires lids for each
drawer. The Wood appliance undesirably cools the product in the bin
from only the top. Wood does not include the capability to be a
thaw cabinet.
PCT Patent Application Publication No. WO2005024315 to Wood
provides a drawer storage appliance such as a refrigerator that
includes a closure being a fixed generally horizontal lid and a
container being an open-topped drawer that is movable horizontally
with respect to the lid. The lid has a skirt that depends therefrom
to support a first sealing loop that is a continuous peripheral
downwardly-facing lid seal. The skirt and the lid seal of Wood are
shaped to correspond to and cooperate with a second sealing loop
that is a continuous upwardly facing sealing surface around the
upper peripheral rim defined by generally vertical walls of the
drawer. Again, Wood undesirably requires lids, in this case, having
a seal between the lid and drawer. The horizontal seal described in
Wood is undesirable with its sealing plane being parallel to the
drawer operation. When temperatures of the appliance interior are
below freezing this may cause the seal to freeze and render the
drawer inoperable because of the large shear plane forces being
placed on the gasket seal.
PCT Patent Application Publication No. WO2005024314 to Wood
provides a refrigerator including a refrigerant circuit having a
compressor, a condenser, an expansion means and an evaporator. The
evaporator includes a branched portion having a plurality of
parallel branches each having a respective evaporator of the
evaporator means. A four-compartment arrangement is also provided.
Each compartment is cooled by a respective evaporator on respective
parallel branches of the circuit. The compartments can be used as a
refrigerator or as a freezer by a mass control achieved by cycling
a respective solenoid shut-off valve serving each evaporator. Each
branch of the circuit is served by a respective thermal expansion
valve whose superheat sensor is downstream of the evaporator of
that branch. Wood, as described above, is doing the same operation,
which has been done for years in refrigerated appliances.
The Wood prior art described above has a drawer gasket having a
disadvantage in that its sealing plane is parallel to the drawer
operation. When temperatures of the appliance interior are below
freezing this may cause the seal to freeze and render the drawer
inoperable because of the large shear plane forces being placed on
the gasket seal, as discussed above. The use of the insulated tubs
described in the Wood prior art described above are not compatible
with standard, readily available foodservice containers. Also, the
airflow around the food product/container is only from the top.
Accordingly, there is a need for an improved refrigeration system
that is capable of multi-faceted operation and allows for varied
storage space. There is also a need for an improved refrigeration
system that is capable of cooling a product on all sides by
providing even air-flow around all sides of a containment bin.
There is a further need for a seal that is perpendicular to the
drawer operation. There is an additional need for a method that
circulates air around the entire food product/container.
SUMMARY OF THE INVENTION
A storage system that has variable temperature is provided. The
system includes one or more drawers. The one or more drawers are
independently operable of one another. A heating and cooling system
is in thermal communication with the one or more drawers. The
heating and cooling system generates even air-flow around all sides
of the one or more drawers for heating and/or cooling thereof.
A method for heating and/or cooling a storage system is also
provided. The method includes generating even air-flow around all
sides of a plurality of drawers by a heating and cooling system for
heating and/or cooling thereof and operating of each of said
plurality of drawers independently of one another.
The heating and cooling system may have at least one evaporator
located at a rear compartment of the one or more drawers. The at
least one evaporator may have an air duct to distribute cooled air
evenly over a top opening of each of the one or more drawers. The
air duct may have a thermal mass. The thermal mass may be a gel
pack. The heating and cooling system may have at least one
condenser, at least one compressor, and at least one evaporator.
The system may further comprise at least one condenser fan. The
system of may further comprise a display for user input. The one or
more drawers each may have at least one mode selected from the
group consisting of refrigerator mode, freezer mode, thaw cabinet
mode, blast chiller mode, and any combination thereof. The one or
more drawers may be free of lids.
The heating and cooling system may have at least one evaporator
located at a rear compartment of the plurality of drawers. The at
least one evaporator may have an air duct to distribute cooled air
evenly over a top opening of each of the plurality of drawers. The
air duct may have a thermal mass. The thermal mass may be a gel
pack. The method may further comprise detecting a temperature in
the plurality of drawers. The method may further comprise storing
one or more parameters of the heating and/or cooling a storage
system in a memory. The method of may further comprise inputting
one or more predetermined parameters. The operating the plurality
of drawers may comprise independently operating each of the
plurality of drawers in a mode selected from the group consisting
of refrigerator mode, freezer mode, thaw cabinet mode, and blast
chiller mode. The method may further comprise sounding an alarm to
indicate a predetermined condition.
The above-described and other features and advantages of the
present disclosure will be appreciated and understood by those
skilled in the art from the following detailed description and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a refrigeration system of the
present invention;
FIG. 2 schematically depicts a cross-sectional side view of a
drawer of the refrigeration system;
FIG. 3 is an exploded view of the refrigeration system;
FIG. 4 is a rear cross-sectional view of the refrigeration system;
and
FIG. 5 is a display of the refrigeration system.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 through 5, an exemplary embodiment of a
refrigeration system generally referred to by reference numeral 10
is illustrated. Refrigeration system 10 has a storage temperature
that may be varied throughout the day, week, or any time period
based on items being stored therein and multi-faceted operation to
provide one or more storage spaces that may be operated
independently of one another. The refrigeration system 10 provides
heat transfer to contents therein on all sides by providing even
air-flow around all sides of containment bins or drawers.
Refrigeration system 10 has storage space and supports 35. Supports
35 may be casters, adjustable legs, any analogous support, or any
combination thereof. Refrigeration system 10 may have any storage
space configuration. Refrigeration system 10 may have one or more
drawers 15, such as, for example, a two drawer configuration or a
four drawer configuration. One or more drawers 15 may be in a side
by side configuration to accommodate a low profile application or
in a stacked configuration as shown in FIG. 1. The stacked
configuration may also provide a work counter 20 above a topmost
drawer of one or more drawers 15. Each drawer 15 may be a full
extension drawer. Each drawer 15 may have a storage capacity to
hold two 6 inch deep hotel pans, and an interior compartment of
each drawer 15 may be about 28 inches wide by about 26 inches deep
by about 10.5 inches high. Refrigeration system 10 may have any
size, such as, for example, a height of about 34 inches to about 36
inches.
The particular type, including materials, dimensions and shape, of
refrigerator system 10 and one or more drawers 15 that are utilized
can vary according to particular storage needs. Refrigerator system
10 may be any material, for example, stainless steel, stainless
steel having Acrylonitrile Butadiene Styrene (ABS) vacuum formed or
high density polyethylene, or a combination thereof refrigerator
liners. A thermal mass 80 may be designed into a top air duct 75.
One or more drawers 15 may be any material, such as, are stainless
steel. One or more drawers may be stainless steel having
Acrylonitrile Butadiene Styrene (ABS) vacuum formed refrigerator
liners, internal trays, and the like. Thermal mass 80 is a medium,
for example, a gel pack, that provides mass to allow refrigeration
system 10 to operate at a more consistent temperature, reduce
number of refrigeration cycles, lower energy consumption as if
partially loaded with product.
Refrigeration system 10 has a heating and cooling system 55 that
includes condenser 60 and compressor 40. Compressor 40 may cycle on
suction pressure. The suction pressure may be determined by
settings for each of one or more drawers 15. Compressor 40 may have
a 120VAC/60 cycle or 240VAC/50 cycle compressor. The two drawer
configuration may have a single condensing coil with one 1/3
horsepower compressor. The four drawer configuration may have two
condensing coils in series with two 1/3 horsepower compressors
operating in parallel.
The two compressors in the four drawer configuration may have a
first compressor operating as a duty compressor and a second
compressor operating as a standby compressor. Pump down on the
first compressor, preferably, is always -20 degrees Fahrenheit. The
first compressor may be activated when there is a preselected first
on pressure in drawer 15 and the second compressor may be activated
when there is a preselected second on pressure in drawer 15. The
first compressor may be deactivated on pump down at -20 degrees
Fahrenheit and the second compressor may be deactivated when there
is a preselected second off pressure in drawer 15. The preselected
first on pressure is, such as, for example, about 72 pounds per
square inch and about 5 degrees Fahrenheit below a lowest set point
temperature. The preselected first off pressure is, such as, for
example, about 16 pounds per square inch. The preselected second on
pressure, for example, is about 78 pounds per square inch and about
2 degrees Fahrenheit below a lowest set point temperature based on
pressure. The preselected second off pressure, for example, is
about 66 pounds per square inch and about 10 degrees Fahrenheit
below the lowest set point temperature based on pressure. The two
compressors may both operate during loads greater than a
preselected heavy compressor operating load, for example, about 78
pounds per square inch.
The two compressors may alternate as the duty compressor and the
standby compressor. Preferably, the two compressors alternate after
a predetermined compressor operating time. Thus, wear is more
equally distributed among the two compressors. The cycling,
preferably, only occurs when both compressors are off. A standard
accumulative on time, preferably, is about 10 minutes. When one of
the two compressors fails, the other compressor may become the duty
compressor.
The particular type, including materials, dimensions and shape, of
the condenser that is utilized can vary according to particular
needs of refrigeration system 10. An example condenser is
rectangular in shape and of tube and fin construction, constructed
of copper or steel tubes with aluminum or steel corrugated fins
which, maximizes heat exchange.
Refrigeration system 10, preferably, has one condenser fan 65 in
the two drawer configuration and two condenser fans 65 in the four
drawer configuration. Condenser fan 65, preferably, is a 120VAC/60
HZ or 240V/50 HZ condenser fan. One or more condenser fans 65 may
operate based on a condenser temperature or a condenser outlet
temperature. The one or more condenser fans and one or more
compressor fans may operate either together, one at a time, or off
based on demand. The four drawer configuration, preferably, has a
primary condenser fan and a secondary condenser fan. The primary
and secondary condenser fans maintain a constant head pressure
based on a condenser temperature and operates at a maximum
efficiency. The primary condenser fan may be activated at a first
condenser fan on temperature, for example, of about 91 degrees
Fahrenheit, and deactivated at a first condenser fan off
temperature, for example, of about 81 degrees Fahrenheit. A second
condenser fan may be activated at a second condenser fan on
temperature, for example, of about 100 degrees Fahrenheit, and
deactivated at a second condenser fan off temperature, for example,
of about 91 degrees Fahrenheit. Similar to the first and second
compressors, the primary and secondary condenser fans, preferably,
cycle between the first and second compressors to even wear.
Each drawer 15 may have an evaporator assembly 70, as shown in FIG.
2. Evaporator assembly 70 is located at a rear compartment 25 of
one or more drawers 15. Evaporator assembly 70, preferably, has air
duct 75 to distribute cooled air evenly over a top opening 30 of
each of one or more drawers 15, as shown by arrows A. Air duct 75
distributes air evenly on all sides 16 of each of one or more
drawers 15 by heating and cooling system 55 generating even
air-flow around all sides 16 for heat transfer therewith, as shown
by arrows B. The cooled air may be distributed by one or more
evaporator fans, and more preferably, two three inch twelve volt DC
fans.
Each drawer 15 may have one or more output devices. Preferably, the
output devices are one or more drawer cooling fans, a hot gas
solenoid, and/or a refrigerant solenoid. The drawer cooling fans
operate during any or all of the operating modes. When drawer 15 is
opened allowing access to the contents, the one or more cooling
fans, preferably, are deactivated. The drawer cooling fans,
preferably, are 12 Voltage Direct Current (VDC), 2.6 w cooling
fans. The hot gas solenoid, preferably, is a 120VAC/0.1 A or
240VAC/0.1 A hot gas solenoid. The refrigerant solenoid controls a
flow of refrigerant during the modes of operation. The
refrigeration solenoid, preferably, is controlled by the
refrigeration drawer temperature set point and defrost cycle time.
The refrigeration solenoid, preferably, is a 120VAC/0.1 A or
240VAC/0.1 A refrigeration solenoid.
Refrigeration system 10 has one or more input devices, and more
preferably, a plurality of sensors. The sensors may include a
condenser temperature sensor, a condenser outlet temperature
sensor, a suction temperature sensor, and a suction pressure
sensor. One or more drawers 15 may have one or more input devices,
and more preferably, a plurality of sensors, such as, for example,
at least one of a box temperature sensor to detect a drawer
temperature in an interior of drawer 15, a defrost temperature
sensor to detect a predetermined defrost temperature, and a drawer
closed sensor to detect if drawer 15 is closed.
The one or more sensors of refrigeration system 10 and one or more
drawers 15 may be in communication with a programmable machine
and/or software, and is more preferably in communication with a
computer program product having a computer useable medium with a
computer readable code means embodied in the medium designed to
implement the specified parameters. For example, a control
processing unit (hereinafter CPU) is in communication with the one
or more sensors. The particular devices and/or sensors described
above can be chosen by one of ordinary skill in the art to
facilitate gathering of data.
Refrigeration system 10, preferably, the CPU, has a memory. The
memory stores all parameters of refrigeration system 10, such as,
for example, a predetermined defrost duration, the predetermined
defrost temperature, predetermined defrost cycle time, condenser
temperature, condenser outlet temperature, constant head pressure,
maximum efficiency, preselected heavy compressor operating load,
predetermined compressor operating time, refrigeration drawer
temperature set point, freezer drawer temperature set point, thaw
cabinet set point, lower blast chiller drawer set point, blast
chiller time period, and/or preselected default set points.
Preferably, the memory stores any or all of the parameters at
parameter intervals for a memory duration, more preferably, the
memory stores any or all of the parameters for 30 days at 5 to 10
minute intervals, as listed in Table A.
TABLE-US-00001 TABLE A Parameter Description Parameter Default
Units Range Comments Refrigeration Box Temperature RBT 37.degree.
F. .degree. F. 32 to 41.degree. F. Freezer Box Temperature FBT
-5.degree. F. .degree. F. -5 to 5.degree. F. Thaw Box Temperature
TBT 37.degree. F. .degree. F. 32 to 50.degree. F. Thaw Box
Hysteresis TBH 638 F. .degree. F. 63 to 658 F. Defrost Coil
Temperature DCT 55.degree. F. .degree. F. 40 to 70.degree. F.
Defrost Duration Time DDT 15 M Minutes 0 to 30 M Intervals between
Defrosts IBD 360 M Minutes 180 to 480 M Suction Pressure SP NA PSI
NA Condenser Temperature CT NA .degree. F. NA Compressor Outlet
Temperature COT NA .degree. F. NA Primary Condenser on Temperature
PFO 91.degree. F. .degree. F. Primary Condenser off Temperature PFF
81.degree. F. .degree. F. Secondary Condenser on Temperature SFO
100.degree. F. .degree. F. Secondary Condenser off Temperature SFF
91.degree. F. .degree. F. Primary Compressor on Pressure PCN NA PSI
Primary Compressor off Pressure PCF NA PSI Secondary Compressor on
Pressure SCN NA PSI Secondary Compressor off Pressure SCF NA PSI
Blast Chill Temperature BCT 23.degree. F. .degree. F. Blast Chill
Time Limit BCL 90 M Minutes Units UNT STD STD or Metric Recording
time intervals RTI 5 M Minutes 5 to 10 M Drawer Timeout Alarm DTA 5
M Minutes 1 to 15 M
Refrigeration system 10 may operate with an operating power between
85 and 264 VAC with an output of 12 VDC. A power supply 300 may
connect to refrigeration system 10 to supply the operating power.
Power supply 300 may have a battery backup to maintain control
operation.
Refrigeration system 10 has a communication device. Preferably, the
communication device includes a National Association of Food
Equipment Manufacturer (NAFEM) Data protocol. The NAFEM Data
Protocol may govern data exchange between refrigeration system 10
and computer based servers. Refrigeration system 10 has a display
50, as illustrated in FIG. 5, and preferably, a liquid crystal
display. The liquid crystal display may be backlit with resolution
to display characters down to 5/32 inch in height. Display 50 may
have a four-button membrane switch 55 for user input. Display 50
may have an adhesive boarder 57 around membrane switches 55 and
display 50.
In use, each of one or more drawers 15 of refrigeration system 10
has at least one of a plurality of operation modes selected from a
refrigerator mode, freezer mode, thaw cabinet mode, and blast
chiller mode, and any combinations thereof. One or more drawers 15
may operate in any one of the operation modes at any time
independently of another drawer 15.
The refrigerator and freezer modes operate similar to conventional
commercial units. The refrigerator mode operates as a refrigerator
in drawer 15 at a refrigeration drawer temperature set point.
Preferably, the refrigeration drawer temperature set point is in a
range from about 32 degrees Fahrenheit to about 41 degrees
Fahrenheit and has a default refrigeration drawer temperature set
point of about 37 degrees. Freezer mode operates as a freezer in
drawer 15 at a freezer drawer temperature set point. Preferably,
the freezer drawer temperature set point is in a range from about
-5 degrees Fahrenheit to about 5 degrees Fahrenheit and has a
default freezer drawer temperature set point of about -5 degrees.
Refrigeration and freezer modes may further include one or more
defrost cycles that run successively in drawer 15. The one or more
drawer cooling fans, preferably, are activated while drawer 15 is
closed and deactivated when drawer 15 is open while in both the
refrigerator and freezer modes. Preferably, during the
refrigeration and freezer modes, the refrigeration drawer
temperature set point is determined by the drawer temperature.
Preferably, during the freezer mode, the freezer drawer temperature
set point is determined by the drawer temperature.
The thaw cabinet mode maintains drawer 15 at a thaw cabinet set
point using hot gas and refrigeration as required. For example, if
the drawer temperature is 3 degrees Fahrenheit below 37 degrees
Fahrenheit, the hot gas solenoid will open in drawer 15 until
drawer 15 reaches 37 degrees Fahrenheit. If the box temperature
rises 3 degrees Fahrenheit above 37 degrees Fahrenheit, the
refrigeration solenoid will open for drawer 15 until the drawer
temperature reaches 37 degrees Fahrenheit. Upon completion of the
thaw cabinet mode, drawer 15 may operate in refrigerator mode, and
more preferably, if drawer 15 does not require hot gas from the hot
gas solenoid for a time, for example, 15 minutes, then
refrigeration system 10 changes the operation mode to refrigeration
mode, sounds an alarm, and displays a message on display 50. The
thaw cabinet temperature set point, preferably, is in a range from
about 32 degrees Fahrenheit to about 50 degrees Fahrenheit and has
a default thaw cabinet temperature set point of about 37 degrees.
Thaw box may have a thaw box hysteresis with a range of about 63
degrees Fahrenheit to about 65 degrees Fahrenheit and a default
thaw box hysteresis of about 63 degrees Fahrenheit. Preferably, the
one or more drawer cooling fans are activated at all times during
the thaw cabinet mode. Thus, the thaw mode allows the user to place
food in a frozen state in any of one or more drawers 15 and thaw
the food at a safe temperature at a maintained drawer temperature
by running refrigeration system 10 in the refrigerator mode and
running the hot gas from the compressor through an evaporator coil
(similar to a hot gas defrost) if the drawer temperature falls too
far. Therefore, the food is thawed at a fastest rate without
subjecting the food to temperatures that could allow growth of
harmful bacteria.
The blast chiller mode reduces the drawer temperature to a lower
blast chiller drawer set point. The lower blast chiller drawer set
point is lower than the drawer temperature in the refrigerator mode
to reduce a content temperature of contents stored in drawer 15
within a blast chiller time period, such as, for example, of 4
hours. The lower blast chiller drawer set point, preferably, has a
default lower blast chiller drawer set point of about 23 degrees
Fahrenheit. The blast chiller time period, preferably, has a
default lower blast chiller time period of about 90 minutes, and
more preferably, drawer 15 will remain at about 23 degrees
Fahrenheit for about 90 minutes and then begin the defrost cycle.
At the end of the defrost cycle, refrigeration system 10 may change
to the refrigerator mode. Preferably, the one or more drawer
cooling fans are activated at all times during the blast chiller
mode. Thus, the blast chiller mode controls a decrease in
temperature to reduce a temperature in food stored in one or more
drawers 15 to a safe temperature.
The hot gas solenoid controls defrost cycles of the refrigeration
and freezer modes and/or the thaw cabinet mode. A defrost cycle
uses hot gas for a predetermined defrost duration, for example, 15
minutes, and/or until a hot gas solenoid coil reaches the
predetermined defrost temperature, such as, for example, 55 degrees
Fahrenheit. After the defrost cycle, drawer 15 returns to the
operation mode the drawer 15 was in prior to the defrost cycle.
Upon the expiration of a predetermined defrost cycle time another
defrost cycle may be activated. The predetermined defrost cycle
time is, for example, 6 hours, may lapse between one defrost cycle
and a subsequent defrost cycle. The predetermined defrost cycle
time, predetermined defrost duration, and/or the predetermined
frost temperature may be adjustable, preferably, from the third
access level. The hot gas solenoid may have a hot gas solenoid
temperature ranging between about 40 degrees Fahrenheit to about 70
degrees Fahrenheit and a default hot gas solenoid temperature of
about 55 degrees Fahrenheit. The predetermined defrost duration,
preferably, ranges between about 0 minutes to about 30 minutes and
has a default predetermined defrost duration of about 15 minutes.
The predetermined defrost cycle time, preferably, ranges between
about 180 minutes to about 480 minutes and has a default
predetermined defrost cycle time of about 360 minutes. Preferably,
the one or more drawer cooling fans are deactivated at all times
during the defrost cycle.
Refrigeration system 10 may have different user access levels. Each
level of access may be obtained by a different pattern of
keystrokes. A first level of access allows the user to change the
mode of operation, for example, between the refrigerator mode,
freezer mode, and thaw cabinet mode. A second level of access
allows the user to change the mode of operation, such as, for
example, between the refrigerator mode, freezer mode, and thaw
cabinet mode and adjust temperature parameters within the modes of
operation. A third level of access allows the user to adjust
parameters that affect operation of refrigeration system 10, for
example, set points for the one or more defrost cycles and/or
adjusting on/off points for the condenser fan. The refrigeration
system 10 may return to preselected default set points in the third
level access.
Refrigeration system 10 may have faults and alarms. Faults and
alarms may be controlled by the CPU. Preferably, the following
conditions when met will sound an alarm and show a message on
display 50 to inform the user of an action or measure that should
be taken: end of thaw cycle, end of the blast chill cycle, loss of
power to alarm, drawer open for more than a set time, for example,
30 seconds, the drawer temperature is 10 degrees Fahrenheit above
or below a temperature for more than a set time, such as, for
example, 10 minutes, a blocked condenser coil, failed thermocouple,
failed pressure sensor, loss of compressor, and/or loss of
condenser. The fault and/or alarm will remain displayed on display
50 until rectified to inform the user that service is required for
the blocked condenser coil, failed thermocouple, failed pressure
sensor, loss of compressor, and/or loss of condenser. The blocked
condenser alarm, preferably, is determined by a difference between
a condenser temperature and a compressor outlet temperature that is
less than a predetermined value. All faults and alarms, preferably,
are noted in the memory. The alarm may be shut down with the touch
of any button or will shutdown after a set alarm/fault period.
Advantageously, refrigeration system 10 does not require lids for
each of one or more drawers 15. Refrigeration system 10 provides
heat transfer to one or more drawers 15 on all sides including top
opening 30 to provide even air-flow around all sides of containment
bins. Refrigeration system 10 includes the capability to be a thaw
cabinet. Refrigeration system 10 does not require a seal that when
temperatures of the appliance interior are below freezing may cause
the seal to freeze and render the drawer inoperable because of the
large shear plane forces being placed on the gasket seal.
Refrigeration system 10 is compatible with standard, readily
available foodservice containers.
While the instant disclosure has been described with reference to
one or more exemplary embodiments, it will be understood by those
skilled in the art that various changes may be made and equivalents
may be substituted for elements thereof without departing from the
scope thereof. In addition, many modifications may be made to adapt
a particular situation or material to the teachings of the
disclosure without departing from the scope thereof. Therefore, it
is intended that the disclosure not be limited to the particular
embodiment(s) disclosed as the best mode contemplated for carrying
out this invention.
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